Table of Contents
Advertisement
VOICE APPLICATIONS
Voice over frame relay can be accomplished using the Express 5210
with an optional dual voice card installed (Dual FXO, FXS, or E&M
card). The following sections describe voice application examples
using the Express 5210. Examples include switched mode (page
5-9), daisy-chaining (page 5-11), PLAR mode (page 5-12), and direct
FXS/FXO (page 5-13).
Switched Mode Application
Switched mode is used to multiplex several remote extensions (up
to 40) to two host ports (see Figure 5-5). This enables many remote
users to have access to a limited number of access lines on a call-by-
call basis. The host unit typically connects two extensions to a PBX
via an FXO module. The remote units connect to telephone sets via
FXS modules.
The host unit is programmed with the extensions and DLCI
information for all of the remote units. This information is
communicated to the remote units over the network.
External Call Origination
When the telephone set on a remote Express 5210 is taken off-hook,
the remote Express 5210 generates dial tone and waits for an
extension to be entered by the user. Once the extension is entered,
the remote Express 5210 transmits this information to the host
Express 5210, where it is compared to extension information in the
extension/DLCI table. If the extension is not located, the host
assumes the number is external and attempts to seize an available
port and dial the extension on the PBX. If no port is available, a
trunk busy (fast busy) is returned to the remote port. After the
extension is dialed, the data link is established and the call remains
up until the remote Express 5210 terminates the call.
External Call Reception
When an incoming call is received from the PBX, the remote
Express 5210 auto-answers the call and generates a dial tone. At
this point, the calling party can dial the extension of the party they
61200208L1-1
Express 5210 User Manual
Chapter 5. Applications
5-9
Advertisement
Table of Contents
